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Mining and Extraction
Lecture
Lecture Purpose: Learn how we mine and extract
the ores and minerals we use every day. Think about the
sustainability of this resource use for your family’s
EcoFootprint.
You will need your Note-Taking Tool for Audit
Proposals.
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What Do We Mine?
 Our
civilization depends on the mining of many
different minerals:
Iron = steel
 Copper = pipes, electrical wires…
 Aluminum (via bauxite ore) = packaging, products…
 Lead = batteries, medical x-ray protection…
 Tungsten = incandescent light bulbs, alloy in metals…
 Uranium = nuclear power industry
 Gold, silver, and many, many more…
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Types of mining
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In order to extract the minerals and metals in the earth’s
crust, various techniques have been developed to mine ores
and to separate residual rock and materials from the valuable
resources.

Ores consist of concentrated accumulation of economically
valuable minerals and metals.
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Two kinds of mining take place on land:
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SURFACE MINING
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SUBSURFACE MINING
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Surface mining
STRIP MINING
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Removes strips of soil and rock to expose ore.
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Strip mining is used when ore is relatively close to the Earth’s surface
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Ex: sedimentary materials such as coal and sand are located close
to the surface
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Once the resource is extracted, the waste material (called mining
spoils or tailings) is returned to the hole created by mining.

A variety of
strategies can be
used to restore
the affected
area to something
close to original
conditions.
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Surface mining
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OPEN-PIT MINING

Creates a large pit or hole in the ground.

Used when resource is close to the surface but extends beneath the
surface horizontally and vertically (ex. copper mines)
Kennecott Bingham
Canyon Mine near Salt
Lake City, UT, is one of
the largest open-pit
mines in the world
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Surface mining
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MOUNTAINTOP REMOVAL
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Miners remove the entire top of a
mountain with explosives.
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Large earth-moving equipment
removes the resource (for
example, coal).
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Tailings are deposited in nearby
lower-elevation regions, often in
or near rivers and streams
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Surface mining
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PLACER MINING
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The process of looking for metals and precious stones in river
sediments.

River water is used to separate heavier items like diamonds,
tantalum, and gold, from lighter items like sand and mud. (ex.
California gold rush)
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Subsurface mining
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Subsurface mining is used when
resources are more than 100
meters (328 feet) below Earth’s
surface.
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Begins with a horizontal tunnel dug
into the side of a mountain or
feature.

Vertical shafts are drilled from the
horizontal tunnel.
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Elevators are used to bring miners
down to the resource and back to
the surface.
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Resources that often require
subsurface mining include coal,
diamonds, and gold.
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Stop & Think…

What were the most important ideas from this section of the
lecture? Tell a partner.

Which types of mining do you think cause the most and least
harm to the environment? Explain why with evidence from
the lecture.

Why does knowing about mining practices matter to our
investigation of our EcoFootprint?

Note-Taking Tool for Audit Proposals: Record your
answers

For citation purposes, you can put down this lecture title, or refer
to Chapters 12 and 19 for more detail.
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and the environment
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The extraction of minerals has various environmental impacts and
human health consequences
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Deposits of spoils and tailings can cause contamination; they can also block
or change the flow of rivers.
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Mining companies may not restore mining sites back to their original states.
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Subsurface mining can cause acid mine drainage, where lower pH water
from the mine is pumped and drained above ground, lowering the pH of
nearby soils and streams.
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Risks to miners:
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Subsurface mining accidents are extremely dangerous
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long term exposure to gases and particles can cause respiratory diseases
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Mining legislation
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Governments have sought to regulate the mining process for many
years:
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The Mining Law of 1872 (General Mining Act) – regulates the mining of
silver, copper, and gold ore as well as fuels, including natural gas and oil,
on federal lands. Written to encourage development and settlement in
the western United States, it contains very few environmental protection
provisions.
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The Surface Mining Control and Reclamation Act of 1997 – regulates
surface mining of coal and the surface effects of subsurface coal mining.
The act mandates that land be minimally disturbed during the mining
process and reclaimed after mining is complete
Mining legislation does not control all of the practices that can have
harmful effects on air, water, and land.
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Working toward sustainability
In the U.S. the Surface Mining Control and Reclamation Act of 1997
requires coal mining companies to restore the lands they have
mined. Regulations also require other types of mining operations to
do some level of restoration.
1.
Fill in the hole or depression in the landscape.
2.
Fill material must be relatively free of metals, acids, and other
compounds and shaped to follow the preexisting contours.
3.
The land must be replanted to re-create the communities of organisms
that inhabited the area before mining.
Properly completed reclamation makes the soil physically stable so
that erosion does not occur and water infiltration and retention can
proceed.
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Uneven distribution of minerals
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Oxygen, silicon, aluminum, and iron are unevenly distributed
over 88 percent of the crust
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Because of uneven distribution, the global supply of mineral
sources are difficult to quantify
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Countries must trade with one another to obtain important
and valuable minerals and metals that are not found within its
territories
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Stop & Think…

What were the most important ideas from this section of the
lecture? Tell a partner – use your notes if needed.
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Increasing human populations and industrialization also
increase the demand for mined resources: How do you think this
will impact…
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the environment?
human health and safety?
social and political relationships between different countries?
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Think like an environmental scientist about your lifestyle:
What modern object could you not live without? What
components in that object are created from mined minerals (and
how would you know)? How would you know about the
sustainability of their source?
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Note-Taking Tool for Audit Proposals: Record your answers

For citation purposes, you can put down this lecture title, or refer to
Chapters 3 and 19 for more detail.